JPH0512781Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a grain detector in a threshing device such as a harvester or a self-propelled threshing machine.

[Prior art]

The threshing device threshes the harvested grain culm with a handling barrel, and extracts fine grains through specific gravity sorting using a swinging sorting device, etc., and removes the grains that have been sorted by the swinging sorting device. The second reduction products such as grains are reprocessed in a processing cylinder or the like.

In order to improve the accuracy of threshing and sorting processes, such threshing machines have been developed to detect the amount of secondary reduction and perform predetermined controls, such as controlling the fin angle in the chaff sheave. ing.

As a reduction amount sensor that detects the second reduction amount,
A grain detector is generally used that is installed in the transport path of the second reductant and utilizes a piezoelectric transducer that is activated by the collision of grains.

[Problem to be solved by the invention] Now, when a grain collides with a piezoelectric transducer, the element vibrates at its natural frequency, so its output voltage is large at the resonant frequency corresponding to the natural frequency. becomes.

Therefore, in conventional grain detectors, only the resonant frequency range of the output of the piezoelectric transducer is extracted, and outputs of other frequencies caused by vibrations of the machine body are removed to improve detection accuracy.

However, the output in the resonant frequency range is due to vibration at the natural frequency of the piezoelectric transducer, and the damping rate is small compared to the output in other frequency ranges. When the grains collide, several peaks appear, and the grain detector incorrectly detects as if several grains have collided, even though the number of grains to be detected is one. When such a grain detector is used as a reduction amount sensor, there is a problem that the accuracy of the threshing process and sorting process performed based on the detection result is reduced.

This also applies to grain detectors using sound-electric transducers, for example.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a grain detector that can reliably detect the amount of grains.

[Means for solving problems]

The grain detector according to the present invention attempts to prevent false detection by canceling the signal caused by resonance among the output signals of the element, and is activated by the collision of grains and outputs a predetermined signal. A grain detector for a threshing device using an element, characterized by comprising means for superimposing a signal caused by resonance of the element on the output signal of the element in response to a signal output from the element. shall be.

[Effect]

With this configuration, the resonance component of the output signal of the element is canceled out by the superimposed signal, and only the desired signal component can be extracted.

〔Example〕

The present invention will be described below based on drawings showing embodiments thereof.

FIG. 1 is a perspective view of the appearance of a grain detector equipped with a grain detector according to the present invention during the harvesting period, and FIG. 2 is a partially cutaway longitudinal sectional view of the threshing device.

In the figure, 3 is a threshing device mounted on the upper part of the machine body above the traveling crawler 1, and the reaping section K is located at the front part of the machine body and is composed of a cutting blade 2, a weeding rod 4, a pulling device 7, etc. The grain culm harvested by the threshing device 3 is sent to the threshing device 3 via a lower conveyance device (not shown), where it is threshed, and the threshed grains are sent to the paddy tank 5. . In the figure, 10 is a vertical conveyance chain, the terminal end of which is composed of a feed chain 12 and a ramming rod 13, and the starting end of a grain culm transporting device 11 provided along the handling opening of the threshing device 3. I am making it happen.

The threshing device 3 has a handling barrel 17 having a large number of handling teeth 16, 16, etc. mounted horizontally in a handling chamber 15 formed in the upper part of the machine casing 14, with its axial length direction being the front-rear direction. A handling port is provided extending in the axial direction of the handling cylinder 17, and a receiving net 18 is stretched under the handling chamber 15, and furthermore, a receiving net 18 is provided below the handling chamber 15 so that the handling port 17 can be oscillated approximately parallel to the axial length direction of the handling cylinder 17. A sorting device 19 is provided.

A processing chamber 50 for reprocessing the second reduction product is provided at the upper right side of the handling barrel 17 (near the center of the machine), and the processing chamber 50 has an axial direction extending along the handling barrel 17. A processing cylinder 51 is mounted on a shaft and has a large number of handling teeth 52, 52, .

The oscillating sorting device 19 includes an oscillating sorting board 20 extending in an inclined manner, an angle-variable chaff sheave 21 provided at the lower rear of the oscillating sorting board 20, a stroke rack 22 connected to the rear of the chaff sheave 21, and It is composed of a grain sheave 23 and the like provided below the chaff sheave 21, and the handling cylinder 17 is controlled by a swinging arm 24 that swings in conjunction with a drive source.
It is configured to swing in the longitudinal direction of the axis.

Further, below the swinging sorting device 19, there is a first grain board 2.
5 and the first grain take-out part (first mouth) 27 consisting of the first screw 26, and the second grain take-out part (second mouth) consisting of the second flow grain plate 28 and the second screw 29.
30 is formed.

The grains that have fallen into the first screw 27 are conveyed toward the center of the machine by the first screw 26, which extends horizontally with the axis length direction as the left-right direction, at the bottom of the first screw 27, and are connected to the right end of the first screw 26. The paddy is transported upward by a vertical transport device (not shown) installed in the tank 5.
The grains that are fed into the second port 30 and fall into the second port 30 are
The feed is fed from a second screw 29 extending in the lower part with the axial direction as the left-right direction, to a thrower 47 provided at the right end of the second screw 29.
It is flipped up by the rotation of 7, and the second thrower cylinder 4
8, the roof board processing chamber 50 of the threshing device 3
The processing cylinder 51 is dropped onto the processing cylinder 51 from a processing cylinder cover 53 protruding above the processing cylinder 51 to be reprocessed. A reduction amount sensor 60, which will be described later, is provided on the lower front inner surface of the second thrower cylinder 48 to detect the second reduction substance such as grains to be returned to the processing cylinder.

Reference numeral 33 denotes a winnowing device that is installed at the front lower part of the machine casing 14 and blows the sorting air toward the rear.
4, 35, grain sieve 2
3. The straw, dust, and other waste particles that pass through the chaff sheave 21, the stroke rack 22, etc. and fall above them from the receiving net 18 are conveyed to the rear, and are transferred to the side of the machine casing 14 above the rear of the stroke rack 22. The dust is sucked in by a dust suction/exhaust fan 36 with an open suction port, and is discharged from the machine through a dust exhaust port (third port) 37 at the rear of the machine casing 14.

Now, the second thrower cylinder 48 has its lower end connected to the rear upper side of the rotation area of the thrower 47, and is inclined forward as shown in FIG. , thrower 47
It is designed to be introduced into a processing chamber 50 located at the upper front of the chamber. The reduction amount sensor 60 installed in the No. 2 thrower tube 48 uses a piezoelectric conversion element, and is placed in front of the lower part of the No. 2 thrower tube 48 so that its sensing surface coincides with the inner surface of the No. 2 thrower tube 48. It is attached to the side surface, that is, to the side surface of the second thrower tube 48 in the centripetal direction of the thrower 47 . By arranging the reduction amount sensor 60 in this way, only relatively heavy grains such as ear cut grains and stalk-attached grains among the secondary reduction products collide with the reduction amount sensor 60. Other relatively light straw, dust, etc. pass through the rear side of the second thrower cylinder 48 due to the centrifugal force of the thrower 47, so they do not collide with the reduction amount sensor 60.
It does not affect the detected value.

FIG. 3 is a block diagram of the control system in the threshing machine.

The output of the piezoelectric transducer 60a of the reduction amount sensor 60 is given to a bandpass filter (BPF) 61, and the bandpass filter 61 filters out the output of the piezoelectric transducer 60a caused by the collision of grains. Only the output in the resonant frequency range of the element 60a is passed through, the output at frequencies caused by vibrations of the aircraft body, etc. is removed, and the output is supplied via the amplifier circuit 62 to the integrating circuit 63 for waveform shaping.

The output of the integration circuit 63 is given to a comparison circuit 64, and the comparison circuit 64 converts the output of the integration circuit 63 to a high level based on a predetermined threshold value shown by a dashed line in FIGS. 4 and 6. , low, and the output thereof is given to a monostable multivibrator 65, which outputs the output of the comparator circuit 64 as a rectangular wave signal with a predetermined pulse width.

This output is given to an oscillation circuit 70 via an integrating circuit 66 and a monostable multivibrator 69, and the integrating circuit 66 generates a potential corresponding to the number of rectangular wave signals input during a predetermined period of time. The sorting control section 68 operates to change the fin angle of the chaff sheave 21 in the swinging sorting device 19 in accordance with the potential input from the integrating circuit 66.

On the other hand, the monostable multivibrator 69 operates using the pulse signal of the monostable multivibrator 65 as a trigger, and has a predetermined pulse width, specifically, its resonance frequency, which is determined by considering the resonance attenuation rate of the piezoelectric transducer 60a. When the oscillation circuit 70 receives this signal, it outputs a signal of a predetermined level having the same frequency and opposite phase as the output signal of the piezoelectric transducer 60a, The signal is applied to the output side of the piezoelectric transducer 60a.

Now, the operation of the harvester constructed as above will be explained.

As the machine moves, each grain culm is harvested in the reaping section K and sent to the threshing device 3 one after another.The grain culm is inserted into the handling chamber 15 from the handling port with the tip end thereof inserted into the grain culm transfer device 11. While being transported rearward at the handler 17, the grains are threshed by the handling teeth 16 of the handling cylinder 17. The threshed grains and other grated materials pass through the receiving net 18 and fall onto the swinging sorting device 19, where they are sorted by specific gravity by the swinging of the device 19 and the sorting air from the winnowing device 33. Then, the fine grains that have passed through the fin gaps of the chaff sieve 21 fall into the first opening 27, and the other unthreshed grains and straw waste are transported backward by the sorting wind, and the comparatively heavy ear pieces in the transported material are transported backwards by the sorting wind. Unthreshed grains, such as grains and grains with branches and stems attached, fall onto the stroke rack 22 and are re-sorted, and relatively light straw and dust are directly sucked into the dust suction fan 36 and discharged from the third port 37 to the outside of the machine. be done.

The second reduced material such as unthreshed grains re-sorted by the stroke rack 22 falls into the second port 30, is fed to the thrower 47 by the second screw 29, and is thrown up by the rotation of the thrower 47. The liquid then rises inside the second thrower cylinder 48, passes through the processing cylinder cover 53, falls into the processing chamber 50, and is reprocessed in the processing cylinder 51.

When the No. 2 reduced product rising inside the No. 2 thrower cylinder 48 collides with the detection surface of the reduction amount sensor 60, the piezoelectric conversion element 60a outputs a predetermined signal, and the bandpass filter 61, amplifier circuit 62, comparison circuit 63 ,
Monostable multivibrator 65 and integrating circuit 66
A predetermined signal processing is performed at the reduction amount sensor 6.
A potential corresponding to the number of grains that collided with the grain is outputted, and the grain flow meter 67 instructs the amount of the second reduction product based on this potential, and the sorting control unit 68 determines the location of the second reduction product according to the potential. The fin angle of the chaff sheave 21 is controlled so that the amount is constant.

Now, FIG. 5 is a block diagram of a control system for a threshing device using a conventional reduction amount sensor. The signal processing section of the conventional reduction amount sensor does not include the monostable multivibrator 69 and the oscillation circuit 70, and has the same configuration as the reduction amount sensor 60 other than that, so the corresponding configuration of the reduction amount sensor 60 is ``' is added to the element number and the explanation thereof is omitted.

4 and 6 are time charts showing the state of signal processing in the reduction amount sensor 60 and the conventional reduction amount sensor, respectively. Below, according to these figures, the monostable multivibrator 69 and the monostable multivibrator 69 in the reduction amount sensor 60 and The operation of the oscillation circuit 70 will be explained.

In FIG. 6, the signal output from the piezoelectric transducer 60a' due to the collision of grains passes through a bandpass filter 61', an amplifier circuit 62', and is waveform-shaped in an integrating circuit 63'.
1' passes only the resonant frequency range of the piezoelectric transducer 60a', so the attenuation rate of its output is small, and the output of the integrating circuit 63' becomes a plurality of mountain shapes whose peak values gradually decrease. Comparison circuit 6 that binarizes based on a predetermined threshold value indicated by a chain line
The output of 4' is the magnitude of the threshold value, and the output of integration circuit 6
The monostable multivibrator 65', which varies depending on the magnitude of the peak value of the output of the band pass filter 61' and the attenuation rate of the output of the band pass filter 61', operates using the output as a trigger. 60a' may output a plurality of rectangular waves as shown in FIG. becomes.

On the other hand, in FIG. 4 showing the state of signal processing in the reduction amount sensor 60 according to the present invention,
The output signal from the piezoelectric transducer 60a is given to the comparison circuit 64 via the bandpass filter 61, the amplifier circuit 62, and the integration circuit 63, and at the same time the output of the comparison circuit 64 becomes high level, the monostable multivibrator 65 starts its operation. and outputs a rectangular wave signal with a predetermined pulse width.

Then, the monostable multivibrator 69 which operates using this signal as a trigger simultaneously outputs a rectangular wave signal with a predetermined pulse width, and while this signal is applied, the oscillation circuit 70 synchronizes with the output signal of the piezoelectric transducer 60a. Since a signal with the same frequency and opposite phase is output and superimposed on the output signal of the element 60a, and the subsequent output of the element 60a is canceled out, the output of the integrating circuit 63 becomes a low level, and the output of the comparator circuit 64 becomes low. The output remains at a low level during one pulse of the rectangular wave signal output from the monostable multivibrator 69. The pulse width of the monostable multivibrator 69 is set to correspond to the time required for the level of the output signal at the resonant frequency of the piezoelectric transducer 60a to attenuate to a sufficiently small level, When the pulse ends and the oscillation circuit 70 stops its output, the output of the piezoelectric transducer 60a caused by the previously collided grain has become a sufficiently small value, and the output of the comparison circuit 64 has reached a high level. There is no turning back.

Further, even if the piezoelectric transducer 60a outputs a signal at a certain level, the signal rapidly attenuates to almost 0, and the output from the oscillation circuit 70 is directly input to the comparator circuit 64, Since the level of the output signal of the oscillation circuit 70 is set to a level that does not exceed the threshold value of the comparison circuit 64, the output of the comparison circuit 64 does not change to a high level. That is, the monostable multivibrator 65 of the reduction amount sensor 60 always outputs a rectangular wave signal of one pulse per grain collision, regardless of the magnitude of the attenuation rate of the output from the piezoelectric transducer 60a. The subsequent output potential of the integrating circuit 66 is a potential that accurately corresponds to the number of grains that collided with the detection surface of the reduction amount sensor 60 and the amount of the second reduction material that is conveyed within the second thrower cylinder 48 if reduced. Become.

〔effect〕

As detailed above, in the grain detector according to the present invention, when grains collide with the detection surface, the piezoelectric transducer emits a predetermined signal, and when the level of the signal reaches a predetermined level, At the same time, a signal having the same frequency and opposite phase as the signal is superimposed on the output signal of the piezoelectric transducer to reduce the level of the output signal of the element, thereby reducing the attenuation of the output signal of the piezoelectric transducer due to grain collision. Even when the ratio is small, the output of the grain detector will be a value that accurately corresponds to the amount of grain that collides with the detection surface, and the accuracy of sorting or threshing processing performed based on that output will improve, etc. It has a great effect.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an external perspective view of a harvester equipped with a grain detector according to the present invention, and FIG. 2 is a partially cutaway longitudinal sectional view of the threshing device. , Fig. 3 is a block diagram of the control system of the threshing machine, Fig. 4 is a time chart showing the state of signal processing, and Fig. 5 is a block diagram of the control system of the threshing machine using a conventional grain detector. FIG. 6 is a time chart showing the state of the signal processing. 3... Threshing device, 17... Handling cylinder, 19... Rocking sorting device, 30... Second mouth, 47... Thrower, 4
8...Second thrower cylinder, 60...Reduction amount sensor, 6
0a... Piezoelectric conversion element, 65, 69... Monostable multivibrator, 70... Oscillation circuit.

Claims (1)

[Scope of utility model registration request] In a grain detector for a thresher that uses an element that is activated by the collision of grains and outputs a predetermined signal, a signal caused by resonance of the element is canceled out in response to the signal output by the element. A grain detector for a threshing device, comprising means for superimposing a signal on an output signal of the element.